Oil pressure jack for lifting operation

ABSTRACT

An oil pressure jack assembly including a multiplicity of piston assemblies with guide rods therethrough and a support structure with interconnected dump valves for said guide rods. Each of the piston assemblies include upper and lower clamp holders having downwardly inclined inner peripheries, said guide rods each having a series of step shoulders matable with said clamp holders, both clamps including spring biasing means whereby the lower clamp supports the piston on a step of a guide rod during hydraulic action raising the upper clamp and vice versa.

D t r Matted @tates Patent 1 fltss'muu Murashige ell all, [4 1 M11. 25, W72

[54] (NHL PRESSURE JACK FUR LHF'HHNG 3,028,143 4/1962 Cheskin ..254/l05 @PERA'HUN 3,347,522 10/1967 Reinmann ....254/10@ [72] Inventors: ll-llidelrichi Murasllige, lchikawa; Musao Primary Examiner-Andrew R. .luhasz Simakura, Tokyo, both of Japan Assistant Examiner-David R. Melton [73] Assignee: Kawatetsu llfiizai Kogyo Co. lLtdL, Minato- AlmmeyFldelman' wolffe & Lamar kur Japan 571 AusTnAc'r Filed: May 1970 An oil pressure jack assembly including a multiplicity of piston 21 A 3 N 4,0 521 assemblies with guide rods therethrough and a support struc l 1 pp 1 ture with interconnected dump valves for said guide rods. Each of the piston assemblies include upper and lower clamp [52] USJLl. .lM/W 151, 254/106 holders havin downwardly inclined inner Peri heries Said 11 1 11mm 112 g P [5 l 1 'f C guide rods each having a series of step shoulders matable with [58] Field Of Search H, 105-l07 i clamp holders, h clamps including p g biasing means whereby the lower clamp supports the piston on a step [56] References Cmd of a guide rod during hydraulic action raising the upper clamp UNITED STATES PATENTS and 2,902,256 9/ 1 959 Gustafson ..254/106 4 Claims, 2 Drawing Figures 1 g r W -7 3 1; 2d l l 2 I -10 OllL PlltlESSlUltlE JACllf IFOR Llll 'llllNG @IPERATHON This invention relates to an oil pressure jack for lifting operation suitable to a lift up process of heavy articles, particularly to such lift up process wherein a plurality of unit structures are to be joined together sequentially from the bottom and the joined structure is to be lifted up by the height of a unit structure by means of oil pressure jack, as in the case of construction of towerlike structure such as a chimney or the like.

Since the oil pressure jack to be used for such lift up must move an article of considerable weight, it is stepped along a plurality of guide rods suspended from a supporting device such as a turret in order to lift up the unit structures. In such a case it is required that the oil pressure jack is positively clamped to the guide rods without slip and at the same time each stepping motion which is one of the operations of the oil pressure jack is uniform in the distance of increment.

Since the unit structures to be lifted up in the lift up process are considerably heavy as mentioned above, it is difficult to move those heavy units at one point by a single oil pressure jack and hence an appropriate number of oil pressure jacks of the type mentioned above are jointly used to share the load. Therefore, unless each of those parallelly connected oil pressure jacks is incremented by the same distance for each stepping operation of the lift up process, partial loading will occur, which may cause various troubles.

Furthermore, since the plurality of guide rods suspended from the supporting structure such as turret moves a heavy article, the change in length of the rod may occur or the supporting structure per se, from which the guide rods are suspended, may flex. In addition there exists difference between the manufacturing tolerances of the lift mechanism including the oil pressure jack. Thus a partial load may be applied to one particular guide rod only. This will prevent the lifting operation from being continued smoothly and cause various troubles such as damage of the guide rod to which partial load was applied.

It is, therefore, an object of this invention to provide an oil pressure jack for lifting apparatus, which is able to be positively clamped to guide rods without slip.

it is another object of this invention to provide an oil pressure jack for lifting apparatus wherein each motion thereof, that is every incremental motion along guide rods is kept uniform in the distance of increment.

It is a further object of this invention to provide a lift mechanism wherein a plurality of oil pressure jacks is jointly used to share the load imparted by heavy unit structures and the partial load to the guide rods corresponding to one carrying system, or to the corresponding oil pressure jacks is automatically prevented.

It is still further object of this invention to automatically prevent partial load from being applied to the guide rods corresponding to each of the carrying systems and the oil pressure jacks due to the change in length of the guide rods during the lifting operation, the deflection or flexure of the supporting structure from which the guide rods are suspended, or the difference in manufacturing tolerances of the lift mechanism including the oil pressure jack.

These and other objects, features and advantages of this invention will be apparent from the following more detailed description of the illustrated embodiments.

In the accompanying drawings:

FIG. 1 is a longitudinal sectional view showing the details of the inside of the oil pressure jack for lifting apparatus according to this invention; and

FIG. 2 illustrates an improved manner for supporting the guide rods such that when a plurality of oil pressure jacks are used in a plurality of carrying systems in a lift up process a partial load to the guide rods corresponding to one carrying systems and thus to the corresponding oil pressure jacks is automatically prevented.

In FIG. l, l designates a piston rod of cylindrical structure, 2 designates a piston provided at the top of the piston rod 11, 3 designates a cylinder body, 3a being an upper oil pressure chamber and 3b being a lower oil pressure chamber, 4 is a piston rod guide of cylindrical structure inserted in the cylindrical piston rod 1, the piston rod guide 4 being slideably fitted in an inner periphery of the piston rod l, and the top end of the guide being integrally fixed to the top end of the cylinder body 3. Thus, when the piston rod ll moves up and down the inner periphery thereof will not be brought into direct contact with periphery of a guide rod l3 having a stop shoulder lid on the periphery, as will be described later.

Integrally mounted at lower end of "the piston rod l is a lower clamp holder 5 with its inner periphery formed with a downwardly stretching inclined surface 5a.

Fitted into the lower clamp holder 5 is a clamp 6 comprising a plurality of, preferably three or more, segments and having a truncated conical profile with a center opening. Annular seat 7 is positively mounted on the lower inner periphery of the lower clamp holder 5, and a coiled spring 8 normally adapted to expand is interposed between the clamp 6 and the annular seat 7.

On the upper side of the cylinder body 3 an upper clamp holder of the same shape or substantially same shape as that of the lower clamp holder 5 is integrally mounted. In the upper clamp holder 9 a clamp 10 which is similar to the clamp 6 is mounted and a coiled spring 12 which is normally adapted to expand is interposed between an annular seat Ill which is tightly fitted into the lower inner periphery of the upper clamp holder 9 and the clamp lit).

The lower clamp holder 5 and the piston rod 1 are detachably coupled to each other by suitable means such as bolt, and the upper clamp holder 9 and the cylinder body 3 are also detachably coupled to each other by suitable means such as bolt. Further, the lower clamp holder .5 and the annular seat 7 fitted to the lower section thereof, and the upper clamp holder 9 and the annular seat 1111 fitted! to the lower section thereof are, respectively, coupled to each other by suitable means such as bolts.

13 designates a guide rod mounted in the piston rod guide 4. On the outer periphery of the guide rod 13 there are provided a plurality of stop shoulders M spaced from each other bya distance which is shorter than the stroke of the piston rod 1 (the stroke of the cylinder body 3) by 1(1 25 percent. The stop shoulders 14 are adapted to engage the clamps 6 and 10, respectively.

The unit structures for a towerlike construction such as a chimney or the like are mounted to the lower clamp holder 5 or the cylinder body 3 with appropriate arms or brackets, not shown.

The operation of the oil pressure jack of this invention will now be described.

With the clamp 6 in the lower clamp holder 5 and the clamp 10 in the upper clamp holder 9 being engaged with the stop shoulder 14 of the guide rod 13 as illustrated, oil pressure is applied through an oil pressure pump, not shown, to the upper oil pressure chamber 3a of the cylinder body 3. Then since the clamp 6 in the lower clamp holder 5 integrally mounted to the lower end of the piston rod 1 has been engaged with the stop shoulder M of the guide rod 113, the cylinder 3 is moved upwardly by a predetermined stroke by reaction.

Upon the upward movement of the cylinder 3 the upper clamp holder 9 mounted on the upper surface of the cylinder 3 is also moved upwardly.

As the upper clamp holder 9 moves up, the inclined surface 9a thereof is moved parallelly (as illustrated by a dot and dash line), during which a clearance g sufficient to cause outward movement of the clamp 10 is formed between the inclined surface 9a of the upper clamp holder 9 and the clamp lltThus, the clamp It] is forced upwardly by the action of the coiled spring 12 normally adapted to expand between the annular seat Ill and the clamp l0, and it is moved toward the inclined surface 9a of the upper clamp holder 9 which has been moved parallelly, and moved up along the guide rod 13 as the clamp holder 9 is moved up, and finally engages with the stop shoulder l4 located one step above the guide rod 13.

Then, the oil pressure within the upper oil pressure chamber 3a of the cylinder body 3 is exhausted and oil pressure is applied to the lower oil pressure chamber 3b of the cylinder body 3. Since the cylinder body 3 is not moved because the upper clamp 10 is engaged with the stop shoulder 14 of the guide rod 13, the piston rod 1 is moved up by a predetermined stroke by reaction, and thus the lower clamp holder 5 connected to the lower end of the piston rod 1 is moved up, and the lower clamp 6 therein is engaged with the stop shoulder 14 located one step above the guide rod 13, as in the case of the upper clamp 10.

By repeating the above operation, the oil pressure jack A can be moved up step by step along the guide rod 13.

In constructing the guide rod 13, the upper clamp holder 9 (including the upper clamp 10), the cylinder body 3 (including the piston rod 1) and the lower clamp holder 5 (including the lower clamp 6) are respectively assembled onto the guide rod 13. For the removal of the oil pressure jack A from the guide rod 13, the upper clamp holder 9, the cylinder body 3 and the lower clamp holder 5 may be withdrawn in this order from the upper end of the guide rod 13.

As is clear from the above description, according to the oil pressure jack A of this invention, the oil pressure jack can always be positively clamped to the guide rod without slip in the lift up operation of heavy structure such as slabs of building or construction including unit structures for chimney or other towerlike construction. Furthermore, since each incremental movement along the guide rod is always kept constant in the distance of increment, it becomes possible to carry out the lift up operation smoothly maintaining a desired level.

Now, referring to FIG. 2, designates a supporting structure mounted on a turret, not shown, of any desired type, 13 designates a suspending guide rod which forms a part of the lift mechanism. This guide rod corresponds to the guide rod shown in FIG. 1 and has its upper end linked to a piston 18 of an oil dumper 16 provided on the supporting structure 15. 17 designates a cylinder body for the oil dumper 16.

In FIG. 2, three suspending guide rods 13 are provided for the supporting structure 15 with appropriate separation from each other. Those three suspending guide rods 13 share the load of a heavy structure such as unit structure, not shown. Three oil dumpers 16 are, accordingly, used.

Various sort of oil dumpers may be employed. In essence, the suspending guide rods 13 which form part of the lift mechanism are used as so-called piston rods for the oil dumpers 16 and the oil pressure chambers 19 of the oil dumpers 16 are connected to branches 20a, 20b and 200, respectively, of a common link pipe 20.

Provided at one end of the link pipe 20 is a stop valve 21 and at the other end is a pressure gauge 23 through a gauge cock 22.

. Oil pressure from an oil pump, not shown, is supplied to the oil pressure chambers 19 of the oil dumpers 16 through the one end of the link pipe 20 under no-load condition in which the oil pressure jacks A have been mounted to each of the suspending guide rods 13 as shown in FIG. 1 but a heavy structure such as unit structure has not yet been mounted on the lower clamp holder 5 or the cylinder body 3 with appropriate arms or brackets.

By way of an example, the oil pressure of the oil supplied to the oil dumpers 16 is measured to 10 tons (50 kg./cm.) by the pressure gauge 23, horizontal mounting level of each of the suspending guide rods 13 is adjusted to a minimum tolerance, and the stroke of each of the piston 17 is set to 15 mm. :1

After setting, the stop valve 21 and the gauge cock 22 are closed. Then the suspending guide rods 13 are loaded with the unit structure. During the lift operation of the unit structure, if partial load is applied to, for example, center guide rod 13 to increase stress due to the difference in manufacturing tolerances of the lift mechanisms including the oil pressure jacks A, the difference in the mounting conditions for the lift mechanisms, the elon ation of the suspending guide rods 13 and the deflection of t e supporting structure and thus the stroke of the center oil dumper 16 corresponding to the center guide rod 13 is lowered, for example, by 10 mm., then the oil from the center oil dumper 16 (volume of the oil 21 1 cc.) is branched to the right and left oil dumpers 16 by substantially equal amount through the branch pipe 20b and the link pipe 20, to thereby lift up the right and left suspending guide rods 13 accordingly.

As a result of this operation, the load applied to the center suspending guide rod 13 and hence the corresponding oil jack A is automatically decreased and the load is substantially evenly shared to each of the suspending guide rods 13 and hence to each of the oil pressure jacks A.

With this mechanism, partial load to the guide rods in one supporting system and hence to the corresponding oil pressure jacks can be automatically prevented when a plurality of supporting systems are used in parallel to share the load at common supporting points for a heavy structure such as unit structure.

Furthermore, partial load to the guide rods in each supporting systems and hence to the corresponding oil pressure jacks due to the change in the length of the guide rods during the lift operation, the deflection of the supporting structure from which the guide rods are suspended and the difference in manufacturing tolerances of the lift mechanisms including the oil pressure jacks, is automatically adjusted.

What is claimed is:

1. An oil pressure jack for lifting operation characterized in that clamp holders each having downwardly stretching inclined surface formed on inner periphery thereof are fixed to a lower end of a cylindrical piston rod and an upper end of a cylinder body, groups of clamps each including a plurality of clamps are accommodated within the clamp holders and normally forced upward by coiled springs, said group of clamps, when integrally assembled, forming a truncated conical profile with a center opening, a guide rod is fitted into said piston rod, said guide rod having stop shoulders separated from each other by distance equal to the stroke thereof formed on the outer periphery thereof, and said groups of clamps are clamped to the stop shoulders of said guide rod.

2. The oil pressure jack for lifting operation according to claim 1, wherein the guide rod has stop shoulders separated from each other by a distance shorter than the stroke of the piston rod by 10-25 percent formed on the outer periphery thereof.

3. The oil pressure jack for lifting operation according to claim 1, wherein a cylindrical piston rod guide which is slideably moved longitudinally along the outer periphery of the guide rod is inserted into a link bore of the cylindrical piston rod, the upper end of the piston rod guide is fixed to the cylinder body to prevent the inner periphery of the piston rod from slideable contact with the outer periphery of the guide rod, annular seats are mounted in the lower opening of the upper and lower clamp holders, and clamps and coiled springs are accommodated within the holders.

4. The oil pressure jack for lifting operation according to claim 1, wherein the upper end of the guide rod is coupled to and suspended from the pistons of a plurality of oil dumpers suitably spaced on a support structure of a turret, the oil pressure chambers of the oil dumpers are coupled to a common link pipe, and an appropriate value of oil pressure is applied in advance at no-load condition where load by a heavy structure such as unit structure is not applied to the suspending guide rods. 

1. An oil pressure jack for lifting operation characterized in that clamp holders each having downwardly stretching inclined surface formed on inner periphery thereof are fixed to a lower end of a cylindrical piston rod and an upper end of a cylinder body, groups of clamps each including a plurality of clamps are accommodated within the clamp holders and normally forced upward by coiled springs, said group of clamps, when integrally assembled, forming a truncated conical profile with a center opening, a guide rod is fitted into said piston rod, said guide rod having stop shoulders separated from each other by distance equal to the stroke thereof formed on the outer periphery thereof, and said groups of clamps are clamped to the stop shoulders of said guide rod.
 2. The oil pressure jack for lifting operation according to claim 1, wherein the guide rod has stop shOulders separated from each other by a distance shorter than the stroke of the piston rod by 10-25 percent formed on the outer periphery thereof.
 3. The oil pressure jack for lifting operation according to claim 1, wherein a cylindrical piston rod guide which is slideably moved longitudinally along the outer periphery of the guide rod is inserted into a link bore of the cylindrical piston rod, the upper end of the piston rod guide is fixed to the cylinder body to prevent the inner periphery of the piston rod from slideable contact with the outer periphery of the guide rod, annular seats are mounted in the lower opening of the upper and lower clamp holders, and clamps and coiled springs are accommodated within the holders.
 4. The oil pressure jack for lifting operation according to claim 1, wherein the upper end of the guide rod is coupled to and suspended from the pistons of a plurality of oil dumpers suitably spaced on a support structure of a turret, the oil pressure chambers of the oil dumpers are coupled to a common link pipe, and an appropriate value of oil pressure is applied in advance at no-load condition where load by a heavy structure such as unit structure is not applied to the suspending guide rods. 